Institut für Raumbezogene Informations- und Messtechnik
Hochschule Mainz - University of Applied Sciences

Optical Technologies

The term "Optical Technologies" covers a wide range of concepts and applications which use the properties of electromagnetisc radiation and today take part in nearly any area of everyday life, research and production.

Main competences of our institute in this field relay to digital imagery and camera technologies. We use cameras for precise measurements. Combined with algorithms it is possible to identify elements within images for a later localisation and use for varying mathematical models in relation to surveying needs.

Our existing skills include the treatment and mathematical description of cameras and precision measurments, the development of suitable algorithms for processing images and the mathematical modeling of surveying. Typical fields of applications are in industrial quality control, but also in medicine, metrology or spatial humanities.

Contact Person

Prof. Dr.-Ing. Frank Boochs

Tel.: +49 6131-628-1432
Fax.: +49 6131-628-91432

Prof. Dr.-Ing. Martin SchlĂĽter

Tel.: +49 6131-628-1440
Fax.: +49 6131-628-91440

Projects

Im Rahmen des Aufbaus eines Zentrums zur Präzisionsmess- und Prüftechnik ist das i3mainz neben den Aktivitäten auf dem Gebiet der DKD-Zertifizierung des Kalibrierlabors für optisch...
Industrieroboter gewinnen durch ihre vielfältige Einsetzbarkeit sowohl in vielen Bereichen der Industrie als auch in der Messtechnik an Interesse. In Verbindung mit einem optischen...

Publications

COSCH - Vier Jahre interdisziplinärer Dialog zum Nutzen des kulturellen Erbes.

2017

RTF

KulturBetrieb - Magazin für innovative und wirtschaftliche Lösungen in Museen, Bibliotheken und Archiven








How to optimally record cultural heritage objects? Decision support through connected knowledge.

2017

RTF

EVA Berlin 2017. Elektronische Medien & Kunst, Kultur und Historie 24. Berliner Veranstaltung der internationalen EVA-Serie Electronic Media and Visual Arts, 2017

Optical recording of material cultural heritage (CH) is a multidisciplinary activity where the understanding of cross-disciplinary semantics is vital for a successful completion. In many cases, a lack of understanding of transdisciplinary semantics slows this process down. The end users who are mostly humanities experts lack the technical knowledge of spatial and spectral recording and could therefore demand more than what is actually required or sufficient for the intended CH application. The negotiations between technical experts and the end users are a tedious process. We present a semantic-based decision support system, COSCHKR, that employs reasoning and recommends optimal recording technology(ies) according to the application requirements of the recorded and processed data. COSCHKR is an ontology-based knowledge model that implies the development of semantic technologies within the Semantic Web framework. It represents formalized knowledge of the disciplines involved in the process of optical recording of material CH. The paper describes the applicability of the model in spatial, spectral, and visualization applications and summarises current possibilities and challenges.


Wall Paintings in the Château de Germolles: An Interdisciplinary Project for the Rediscovery of a Unique Fourteenth-Century Decoration

2017

RTF

A. Bentkowska-Kafel, L. MacDonald (eds), Digtial Techniques for Documenting and Preserving Cultural Heritage

The aim of this study was to examine and document the wall paintings in the Château de Germolles. Situated in Burgundy, France, Germolles is the best preserved residence of the Dukes of Burgundy and was listed as a monument of national importance in 1989.
The medieval wall decoration of the Château de Germolles was rediscovered under the nineteenth-century plasters during World War II. Medieval accounts of the château provide a detailed list of the materials acquired to make the mural decoration, but this list is incongruous when compared with the current appearance of the paintings. The discrepancy between the archival and material evidence, and also the need to understand the complexity of the painting technique used were the main motivations for undertaking the case study described in this chapter. Imaging alongside more traditional examination techniques were utilized to record and document the mural decoration. The objectives of the case study were to distinguish the original materials from those applied during restoration, identify those materials, and correlate them with the archives. We also tried to understand the medieval painting techniques used and assess the condition of the paintings and stabilization requirements. Finally we aimed to find a sustainable solution for the management of the various types of data collected. Various techniques and investigations offered valuable insights into the materials and the painting technique used. To improve visitor experience, based on the information gained in the course of this study, a 3D virtual representation of the original decoration is currently proposed for display to the public visiting the Château de Germolles.


Ontology-Based Structuring of Spectral and Spatial Recording Strategies for Cultural Heritage Assets: Background, State of Affairs, and Future Perspectives

2017

RTF

A. Bentkowska-Kafel, L. MacDonald (eds), Digtial Techniques for Documenting and Preserving Cultural Heritage

The activities of COSCH community and the disciplines it represents were as diverse as they could possibly be in research into cultural heritage. To achieve common goals it was of utmost importance to have a common understanding of these diverse activities and disciplines. Work on the COSCH Knowledge Representation, or COSCHKR, was undertaken to develop a common semantic base representing different disciplines and to facilitate communication within the Action. The COSCHKR is an ontology-based inference model, guided by inference rules that provide a semantic bridge between various interdisciplinary activities involved in non-invasive technical documentation of material cultural heritage. The model is intended to support humanities experts by recommending optimal spatial and spectral techniques. The model may also be used by technology experts to compare their own solutions with the ones recommended through COSCHKR, and to understand why they may differ.
In this chapter we present the methods adopted for designing the COSCHKR and the steps in the development of the inference model. The difficulties in maintaining a common level of understanding within the diverse disciplines during the knowledge acquisition process are discussed. We present mechanisms and methods of information collection, its structuring, and aligning, to formulate different axioms and theorems within the model. The design and development of COSCHKR was based on an iterative procedure where the gathered knowledge was first verified with the group of experts before it was processed. This verification mechanism was important for the reliability of the model, ensuring technical consistency. This chapter highlights the importance of these iterative mechanisms in the validation of knowledge gathered and then information populated inside the knowledge base.


Technical study of Germolles’ wall paintings: the input of imaging technique

2016

RTF

Virtual Archaeology Review

The Château de Germolles is one of the rare palaces in France dating from the 14 th century. The noble floor is decorated with wall paintings that are a unique example of courtly love spirit that infused the princely courts of the time. After being concealed sometime in the 19 th century, the paintings were rediscovered and uncovered in the middle of the 20 th century and partly restored at the end of the 1990s. No scientific documentation accompanied these interventions and important questions, such as the level of authenticity of the mural decorations and the original painting technique(s) used in the medieval times remained unanswered. The combined scientific and financial supports of COSCH COST Action and DRAC-Burgundy enabled to study Germolles' wall paintings using some of the most innovative imaging and analytical techniques and to address some of the questions raised. The study provided significant information on the material used in the medieval times and on the conservation condition of the paintings. The data collected is vast and varied and exposed the owners of the property to the challenges of data management.


Development of a platform recommending 3D and spectral digitisation strategies.

2016

RTF

Virtual Archaeology Review

Spatial and spectral recording of cultural heritage objects is a complex task including data acquisition, processing and analysis involving different technical disciplines. Additionally, the development of a suitable digitisation strategy satisfying the expectations of the humanities experts needs an interdisciplinary dialogue often suffering from misunderstanding and knowledge gaps on both the technical and humanities sides. Through a concerted discussion, experts from the cultural heritage and technical domains currently develop a so-called COSCH KR (Colour and Space in Cultural Heritage Knowledge Representation) platform that will give recommendations for spatial and spectral recording strategies adapted to the needs of the cultural heritage application. The platform will make use of an ontology through which the relevant parameters of the different domains involved in the recording, processing, analysis, and dissemination of cultural heritage objects are hierarchically structured and related through rule-based dependencies. Background and basis for this ontology is the fact that a deterministic relation exists between (1) the requirements of a cultural heritage application on spatial, spectral, as well as visual digital information of a cultural heritage object which itself has concrete physical characteristics and (2) the technical possibilities of the spectral and spatial recording devices. Through a case study which deals with the deformation analysis of wooden samples of cultural heritage artefacts, this deterministic relationship is illustrated explaining the overall structure and development of the ontology. The aim of the COSCH KR platform is to support cultural heritage experts finding the best suitable recording strategy for their often unique physical cultural heritage object and research question. The platform will support them and will make them aware of the relevant parameters and limitations of the recording strategy with respect to the characteristics of the cultural heritage object, external influences, application, recording devices, and data.


Knowledge guided object detection and identification in 3D point clouds

2015

RTF

Videometrics, Range Imaging, and Applications XIII, 952804

Modern instruments like laser scanner and 3D cameras or image based techniques like structure from motion produce huge point clouds as base for further object analysis. This has considerably changed the way of data compilation away from selective manually guided processes towards automatic and computer supported strategies. However it’s still a long way to achieve the quality and robustness of manual processes as data sets are mostly very complex. Looking at existing strategies 3D data processing for object detections and reconstruction rely heavily on either data driven or model driven approaches. These approaches come with their limitation on depending highly on the nature of data and inability to handle any deviation. Furthermore, the lack of capabilities to integrate other data or information in between the processing steps further exposes their limitations. This restricts the approaches to be executed with strict predefined strategy and does not allow deviations when and if new unexpected situations arise. We propose a solution that induces intelligence in the processing activities through the usage of semantics. The solution binds the objects along with other related knowledge domains to the numerical processing to facilitate the detection of geometries and then uses experts’ inference rules to annotate them. The solution was tested within the prototypical application of the research project “Wissensbasierte Detektion von Objekten in Punktwolken für Anwendungen im Ingenieurbereich (WiDOP)”. The flexibility of the solution is demonstrated through two entirely different USE Case scenarios: Deutsche Bahn (German Railway System) for the outdoor scenarios and Fraport (Frankfort Airport) for the indoor scenarios. Apart from the difference in their environments, they provide different conditions, which the solution needs to consider. While locations of the objects in Fraport were previously known, that of DB were not known at the beginning. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.


Netzmessungen mit dem Leica Absolute Tracker AT402 zur Bestimmung geodätischer Prüfstrecken

2015

RTF

Allgemeine Vermessungs-Nachrichten (avn)

Zur Bestimmung geodätischer Prüfstrecken unter Nutzung eines Leica Absolute Trackers AT402 stellen wir Konzept und Ergebnisse vor. Dazu greifen wir die positiven Erfahrungen mit Lasertrackern beim Ringversuch auf der neuen Kalibrierbasis der Universität der Bundeswehr München zwischen 2009 und 2011 auf.
Im Unterschied zum Ringversuch konzentrieren wir uns auf die Bestimmung neuer und bestehender PrĂĽfstrecken im derzeit ĂĽblichen Pfeilerdesign mit einer Pfeilerkopf-Abschlussplatte mit 5/8-Zoll-Gewindezapfen zur DreifuĂźaufnahme. DafĂĽr schlagen wir eine Netzmessung unter Verwendung einfacher Pfeiler-Aufsatzadapter vor. AbschlieĂźend vergleichen wir unsere Ergebnisse, die bei unterschiedlichen meteorologischen
Bedingungen auf der Eichstrecke Weinolsheim des Landes Rheinland-Pfalz gewonnen wurden.